This proposal is to request support for a Keystone Symposia meeting entitled "Common Mechanisms in Arrhythmias and Heart Failure", organized by Alfred L. George, Jeffrey A. Towbin and Elizabeth M. McNally, which will be held in Keystone, Colorado from April 2 - 7, 2009. Electrical and mechanical disturbances in heart function underlie most cardiovascular morbidity and mortality. Investigations into the causes of cardiac arrhythmias and heart failure have led to considerable improvements in diagnosis and treatment of these conditions. Recent advances uncovering the molecular genetic basis for familial cardiomyopathy and inherited arrhythmia susceptibility have fueled greater interest in defining common pathophysiological mechanisms. This Keystone Symposia meeting will bring together experts in both fields to exchange ideas and explore common areas of interest. Major areas of emphasis for the symposium will include genetic mechanisms, electrical and transcriptional remodeling, regulation and disorders of cardiac ion homeostasis, and the complex interplay between molecules governing electrical and contractile events in the heart. The goal of this meeting is to stimulate new areas of investigation at the interface between the biology of heart rhythm and contraction, ideally leading to new therapeutic strategies and targets. (End of Abstract)